AAM Building the Bridge to Real Content

Syntax

ALTER TABLE tablename
ADD COLUMN columnname type { [Contraint] [...] };

ALTER TABLE tablename
DROP COLUMN columnname;

Description

With ALTER TABLE you can add, remove or modify table columns. depending on the database management system, the table should not be empty.

Example:

ALTER TABLE tkunden ADD COLUMN new_number INTEGER NOT NULL;

Adds the new INTEGER column new_number to existing table tkunden and sets a NOT NULL contraint.

Example:

ALTER TABLE TABLE tkunden DROP COLUMN new_number;

Drops the column new_number from the table tkunden.